Jeffrey Gundlach, the star investment manager ousted from TCW Group in a shakeup earlier this month, said Monday that he has formed a new firm whose backers include Oaktree Capital Management. The firm’s leaders look to lure away many of their former TCW clients.

DoubleLine LLC will be lead by Gundlach, TCW’s former chief investment officer, and Philip Barach, former group managing director of TCW’s mortgage-backed securities group. They are joined by more than 30 former members of their team at Los Angeles-based TCW, many of whom left after Gundlach was fired Dec. 4.

TCW, which has more than $100 billion under management, replaced Gundlach at the same time it acquired Metropolitan West Asset Management LLC, an L.A. fixed-income investment manager with $30 billion under management.

DoubleLine’s financial backers include Howard Marks, chairman of Oaktree Capital Management, who himself left TCW several years ago during a company shakeup. The size of Oaktree’s minority equity stake in the new firm was not disclosed.

“I’ve known Jeffrey and Phil for over 20 years and supervised them at TCW during a difficult investment period in 1994,” Marks said in a statement. “Given our long history, a shared philosophy that emphasizes the importance of risk control, and the extraordinary performance record that they built at TCW, we were happy to agree to help them establish their new business.”

Oaktree will help DoubleLine establish its own operational infrastructure, according to the announcement. Gundlach, who had been with TCW for 24 years and had been chief investment officer since 2005, was known for his expertise in complex mortgage-backed securities.

“Looking beyond the start-up phase of our firm, I also envision rich possibilities of shared product offerings by blending our team’s core fixed income and mortgage-backed capabilities with Oaktree’s widely recognized franchise in the active management of fixed income and alternative investments,” Gundlach said in a statement.